The invention relates to a drive system based on a double-fed asynchronous motor.
In what is called a power converter cascade of a double-fed asynchronous motor, rotor currents or rotor outputs that occur are usually conducted away by way of slip rings. However, slip rings are susceptible to failure and require maintenance.
The invention is based on the task of making available a drive system based on a double-fed asynchronous motor, which system does not require any slip rings and has improved operating properties as compared with conventional double-fed asynchronous motors.
The invention accomplishes this task by means of a drive system comprising: a three-phase motor, having a shaft, a first three-phase winding set, having: a three-phase stator winding, which is to be connected with a three-phase alternating voltage network, and a three-phase rotor winding, which is mechanically coupled with the shaft, in rotationally fixed manner, and a second three-phase winding set, having: a three-phase stator winding, which is to be connected with the three-phase alternating voltage network in such a manner that as compared with a rotary field that is produced by means of the stator winding of the first winding set, a rotary field that runs in the opposite direction is produced, and a three-phase rotor winding that is coupled to the shaft in mechanical, rotationally fixed manner, a first inverter, which is mechanically coupled with the shaft in rotationally fixed manner, and is electrically coupled with the three-phase rotor winding of the first winding set, and a second inverter, which is mechanically coupled with the shaft in rotationally fixed manner, and electrically coupled with the three-phase rotor winding of the second winding set, wherein the first inverter and the second inverter are electrically coupled in such a manner that electrical power can be transmitted between the inverters, wherein the second inverter is configured for generating triggering signals for its related rotor winding, in such a manner that a resulting motor speed of rotation generated by means of the second inverter corresponds to a motor speed of rotation generated by means of the first inverter, wherein the first and the second inverter are configured for generating triggering signals for their related rotor windings, in such a manner that a direction of effect of a torque generated by the first inverter corresponds to a direction of effect of a torque generated by the second inverter.
The drive system has a three-phase motor, a first inverter, and a second inverter.
The three-phase motor conventionally has a shaft that is driven by the motor.
The three-phase motor furthermore has a first three-phase winding set. The first three-phase winding set has a three-phase stator winding, which conventionally is to be connected directly, particularly without the interposition of an inverter, with a three-phase alternating voltage network to produce a magnetic rotary field. The first three-phase winding set furthermore has a three-phase rotor winding or rotor winding that is coupled to the shaft in mechanical, rotationally fixed manner.
The three-phase motor furthermore has a second three-phase winding set. The second three-phase winding set has a three-phase stator winding, which is to be connected with the three-phase alternating voltage network in such a manner that as compared with the magnetic rotary field that is produced by means of the stator winding of the first winding set, a magnetic rotary field that runs in the opposite direction is produced. The second three-phase winding set furthermore has a three-phase rotor winding that is coupled to the shaft in mechanical, rotationally fixed manner.
The first inverter is mechanically coupled with the shaft in rotationally fixed manner, i.e. it rotates with the shaft, and is electrically coupled with the three-phase rotor winding of the first winding set. The first inverter generates triggering signals in the form of triggering voltages and/or triggering currents having suitable amplitude and phasing.
The second inverter is mechanically coupled with the shaft in rotationally fixed manner, and electrically coupled with the three-phase rotor winding of the second winding set.
The first inverter and the second inverter can be electrically coupled in such a manner that electrical power can be bidirectionally transmitted between the inverters. For this purpose, the first and the second inverter can have an intermediate circuit coupling, for example.
The second inverter can be configured for generating triggering signals for its related rotor winding in such a manner that a resulting motor speed of rotation generated by means of the second inverter precisely corresponds to a motor speed of rotation generated by means of the first inverter.
The first and the second inverter can be configured for generating triggering signals for their related rotor windings in such a manner that a sum of an effective output fed into its related rotor winding by the first inverter and of an effective output fed into its related rotor winding by the second inverter amounts to zero.
The first and the second inverter can be configured for generating triggering signals for their related rotor windings in such a manner that a direction of effect of a torque generated by the first inverter corresponds to a direction of effect of a torque generated by the second inverter.
The drive system can have a fan wheel driven by means of the shaft, wherein the first and the second inverter are coupled with the fan wheel in rotationally fixed manner and thermally coupled with it. The first and the second inverter can be attached at any desired position, for example in the region of the point of rotation of the fan wheel or outside of the point of rotation, on the side or on top of the fan wheel.
The first and the second inverter can be integrated into the fan wheel, for example in that the fan wheel forms a housing for the first and the second inverter.